I've been using an optical cable from my macbook (2009) to play files (mkv, avi, mp4) with Dolby Digital or DTS encoding with no problems for a long time.

Until today.

Now, every time I start one of these files, my output device in the sound prefs panel switches automatically from "Optical Digital-Out Port" to whatver else is avaialble. I've actually gone as far as removing ALL other options except airplay, which I can't delete since that is my receiver, but if the file has encoded output, it just outputs silence since it switches output devices. If I change the output device in VLC to "Built in output" then it plays, but it just uses Pro Logic. I had no troubles with this until today. I just don't get it. I changed nothing.

I tried restoring a Time Machine Backup to the day before this problem started and it worked insofar as I am now hearing sound when the encoding is DTS or Dolby Digital. Oddly, the sound device selection still is jumping to something other than Digital Out...for example, it jumps to "soundflower" but still works.

Hi, I have a Sony STR-K1500 A/V Receiver that has 2HDMI in and 1HDMI out, and a Panasonic LCD, I want to connect to my Mid 2012 MacBook Pro to both my Tv and receiver so i can get true 5.1 surround sound when I watch a movie that has 5.1 sound. I've been searching, and I found that this receiver doesn't handle audio via HDMI. So how do I have to make the connections to my laptop, receiver and tv? Do I have to connect the MacBook Pro to the receiver via hdmi and toslik, and then my Tv to the hdmi out of the receiver? I don't know waht to do, please help me!

Hi, I have a Sony STR-K1500 A/V Receiver that has 2HDMI in and 1HDMI out, and a Panasonic LCD, I want to connect to my Mid 2012 MacBook Pro to both my Tv and receiver so i can get true 5.1 surround sound when I watch a movie that has 5.1 sound. I've been searching, and I found that this receiver doesn't handle audio via HDMI. So how do I have to make the connections to my laptop, receiver and tv? Do I have to connect the MacBook Pro to the receiver via hdmi and toslik, and then my Tv to the hdmi out of the receiver? I don't know waht to do, please help me!

I will apologize in advance as I am not tech savvy as most of the people here. I currently have the imac 27 inch (late 2012) version. I just ordered a logitech z906 5.1 speakers. I'm a very simple person...just want to listen to music, watch movies online, tv shows online, and etc. through my speakers.

I do not video edit, hook up through dvd player and what not. As such, all i want to know is...what cable do i need to enjoy true 5.1 surround sound through my imac? Is it (1) Thunderbolt to HDMI or (2) 3.5 jack and optical cable or (3) BOTH!

Sorry fo the confusion and I'm just starting get familiar with all these technical terms. Also, i read all the previous post...where AUDIO MIDI all the other sections are grayed out besides stereo...what is the purpose of testing all the individual speakers when you mentioned that through 3.5 jack and opitcal, although it shows stereo, it will produce surround sound?

And what if, like me, you don't have an HDMI port and both your mini display ports (thunderbolt ports) are taken up by displays? I am fully aware you can have a 3.5mm optical adapter and use that however then when you change the settings in the Audio MIDI Setup to Encoded Digital Audio it jumps to another output device. Why is this and how do I stop it?

Hello Lance - Glad to learn Logic Pro X can output surround sound via HDMI - I read elsewhere that it couldn't, but I guess that was for pre 2009 Macs. I went through all the preference menus in both Logic & Apple OS and saw how this would work.

But where do you get to choose PCM 5.1 (or LPCM) as opposed to Dolby or other 5.1 protocol ? Is that in the AV amp options ?

And what about coordinating sampling rate & bit depth parameters ? I saw there are some issues here. What do you do your mixing in ?

when you are in 'Audio MIDI setup' and you click on your HDMI device,, on the left of the screen there are 2 options. Input and Output. Are BOTH clickable ??

On mine only the output is clickable.However, when i press configure speakers all 5.1 are working perfectly but none are actually visible in the section below source / format etc. My pioneer receiver is connected to my mac mini via HDMI. The HDMI cable is connected to the IN HDMI on the receiver. Do i need another HDMI cable from the OUT ?? if so, where would it plug to ?? as theres no more jack on the mac mini.

After A long time struggling with this, I found a solution that worked for me that may be the scorce of many other's similar problem.

The mac ----> receiver -----> TV connection is possibly ignoring the receiver and treating it as being connected to the TV that is only capable of stereo output.

A quick way to test if that is the case is to leave the TV either off or disconnected and go to audio midi controller with the use of your Laptop's screen. If all the channels then become present then the TV was the culprit.

Fear not, The solution to the issue with the TV connected is to Set the Recviever's speaker output setting to "amp" or "amp only". For the TV to be interfering, it's likely the receiver was set to "TV&AMP".

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